This invention relates in general to a test fixture for accurately simulating a seating environment within a vehicle and for measuring seat pressure data in response to simulated operation of the vehicle. In particular, this invention relates to a vehicular dynamic ride simulation system that includes both a human biofidelic manikin and a seat pressure distribution sensor array for collecting and displaying dynamic pressure distribution data over a period of time and a variety of operating conditions.
Virtually all vehicles include at least one seat upon which an occupant of the vehicle sits during operation of the vehicle. Such a seat is a primary interface between the occupant and the vehicle. Therefore, it is very important that the seat function not only in a safe and reliable manner, but that it also provide maximum amount of comfort to the occupant thereon. Because of this, seat manufacturers devote a significant amount of their resources to design seats that are comfortable for use within vehicles.
To facilitate the design process, it is important to gather accurate data regarding the operation of a seat during operation of the vehicle. In one known data-gathering method, a human test subject sits upon a seat that is provided within an actual vehicle as it is operated on a road. In a similar known data-gathering method, the human test subject sits upon a seat that is provided within a test fixture which is subjected to a variety of mechanical stimuli that simulate the operation of the vehicle on a road. In both of these known data-gathering methods, a single pressure sensor has been provided that measures the total amount of pressure that is exerted on the entire seat in response to the operation of the vehicle (whether actually on the road or simulated). Although these total pressure sensing systems can provide some useful information to a seat designer, they lack the ability to provide sufficiently detailed information as to how individual areas of the seat will function under highly dynamic conditions.
It is also known to measure a static seating pressure distribution characteristic of a human test subject on a seat. Such a static seating pressure distribution characteristic is essentially a two dimensional representation of the amount of pressure that is exerted by the human test subject upon each of a plurality of individual areas defined on the seat at a single point in time. The measurement of this static seating body pressure distribution characteristic has been accomplished using a relatively flat mat that contains a plurality of individual pressure sensors arranged in a two-dimensional array. Each of the individual pressure sensors within the mat represents an individual area of interest on the seat. Initially, the mat is placed upon a surface of the seat for which measurements are desired to be taken. Then, the human test subject sits upon the mat in a motionless manner. The individual pressure sensors of the mat generate a plurality of individual pressure signals that are used to create the static seating body pressure distribution characteristic. Although this static seating body pressure distribution can provide a quick and economical check to determine if excessive static pressure points exist relative to anatomical landmarks, it has been found that a seat can have comfortable pressure levels under static conditions but still undesirably allow some portions of the occupant to hit a “hard” surface (such as an underlying frame of the seat) under highly dynamic conditions, such as when the vehicle is operated on a relatively rough road.
The adoption of new, thinner-foam technologies in vehicle seats has been hampered by a concern that portions of an occupant of the seat may undesirably “bottom out” on the underlying frame when the vehicle is operated over a relatively rough road. Conventional data-gathering methods, such as those described above, have not proven to be adequate for providing the dynamic seating body pressure distribution data that is needed to resolve this concern. Thus, it would be desirable to provide a vehicular dynamic ride simulation system that includes both a human biofidelic manikin and a seat pressure distribution sensor array for collecting pressure distribution data over a period of time and a variety of operating conditions.